微小电极夹持送进机构设计

设计实现了一种微小电极丝送进机构，使电极丝在随主轴旋转并在轴向高精度的伺服进给控制下，可实现电极丝长距离的送进及损耗自动补偿。其中电极丝的夹紧切换由一个常闭夹丝机构和一个常开夹丝机结构执行，常闭和常开夹丝机构可由电磁或形状记忆合金致动控制。     

纳米TiN改性金属陶瓷刀片的铣削性能

制备了两种纳米TiN改性金属陶瓷可转位铣刀片ToolA和ToolB。研究了这两种新型面铣刀在切削正火态45#钢时的铣削性能及其失效机理。试验结果表明,两种试验铣刀片在Vc=294m/min,fz=0.16mm/z,ap=0.5mm条件下铣削45#钢时,均未发现“崩刃”现象,并全都以“磨损”的形式失效,刀具寿命较长。此外,在同样切削条件下,ToolA具有良好的抗氧化磨损性能,而ToolB有更高的耐机械冲击能力;高温扩散和氧化磨损成为导致纳米TiN改性铣刀片磨损失效的主要原因。     

焦炭催化CO-NO反应的动力学实验研究北大核心CSCD

从高炉风口喷吹烧结烟气是一种有别于传统烟气脱硝工艺的新思路。为探究烧结烟气喷入风口后,焦炭催化CO-NO还原反应的动力学过程,实验以CO、NO气体为原料,以焦炭为催化剂,将不同流量配比的CO和NO混合气体在炉温为850~975℃时通入炉内,在出口处测量CO和NO反应后体积分数。实验结果表明,焦炭对CO还原NO反应有明显的催化作用;反应温度不变,CO和NO的流量比增大时,NO的还原率会增大;CO和NO的流量比不变,温度增大时,NO的还原率也会增大;炉温850、900、925、950、975℃时,反应速率常数分别为0.56、0.88、0.78、1.28、1.38 m^(3)/(mol·s),通过拟合动力学参数得到反应的活化能E;为84.1 kJ/mol。     

节能降碳的蓄热式加热炉烟气反吹关键技术

摘要：蓄热式加热工艺是大型钢铁企业轧钢工序普遍采用的加热技术,但该工艺高频率换向蓄热燃烧导致公共管道内的燃气交替排入大气造成环境污染和能源浪费,使其成为钢铁生产流程中少有未进行污染物治理的生产工序。基于消除蓄热式加热炉热工制度缺陷,系统介绍了蓄热式加热炉烟气反吹扫技术及与之匹配的加热炉烟气反吹安全联锁与防爆技术、烟气反吹工艺设计与时序调控技术。该成果应用于某钢铁企业蓄热式加热炉（160t/h）建设国内首套换向残留燃气反吹技术示范线,该加热炉燃气放散体积分数由9.0%降低至0.208%,CO放散减排率达92%以上,轧钢燃气耗量节约4.38%。其后承建多家钢铁企业19条蓄热式轧钢加热炉烟气反吹改造工程,均取得较好效果,节能、环保及社会效益显著,同时减少碳氧化物的排放量,助力国家实现双碳目标。     

晶化机制与激活能的晶化速率参比法确定

本文根据修正的Kissinger公式提出一种确定非晶材料晶化机制与激活能的最大晶化速率参比法。以Ar_(70)Cu_(30)非晶合金为例,研究了晶化机制与激活能及其与压力的关系。     

Stress relaxation behavior of Ti-6Al-4V alloy

1　INTRODUCTIONTi 6Al 4VisoneofthemostimportantTial loys[1,2 ] .Butthisalloyhasbadformabilityforitshighelasticresilience .Therefore ,hotsizingisimpor tant[36 ] .Asthebaseofhotsizing ,thestudyofstressrelaxationhasimportanttheoreticalvalueandpracticalsignificance .Ontheotherhand ,Ti 6Al 4Visusedasfastenermaterialssometimes .Whenthefastenersworkatthetemperaturehigherthanroomtemperature ,stressrelaxationmayresultsinacci dents .Sohowtopreventthestressrelaxationisveryimportant[7] .Uptonow ,…     

Cold gas dynamic spraying of aluminum: The role of substrate characteristics in deposit formation

Aluminum powder of 99.7 wt.% purity and in the nominal particle size range of −75+15 μm has been sprayed onto a range of substrates by cold gas dynamic spraying (cold spraying) with helium, at room temperature, as the accelerating gas. The substrates examined include metals with a range of hardness, polymers, and ceramics. The substrate surfaces had low roughness (R _a < 0.1 μm) before deposition of aluminum in an attempt to separate effects of mechanical bonding from other forms of bonding, such as chemical or metallurgical bonding. The cross-sectional area of a single track of aluminum sprayed onto the substrate was taken as a measure of the ease of initiation of deposition, assuming that once a coating had begun to deposit onto a substrate, its growth would occur at a constant rate regardless of substrate type. It has been shown that initiation of deposition depends critically upon substrate type. For metals where initiation was not easy, small aluminum particles were deposited preferentially to large ones (due to their higher impact velocities); these may have acted as an interlayer to promote further building of the coating. A number of phenomena have been observed following spraying onto various substrates, such as substrate melting, substrate and particle deformation, and evidence for the formation of a metal-jet (akin to that seen in explosive welding). Such phenomena have been related to the processes occurring during impact of the particles on the substrate. Generally, initiation of aluminum deposition was poor for nonmetallic materials (where no metallic bonding between the particle and substrate was possible) and for very soft metals (in the case of tin, melting of the substrate was observed). Metallic substrates harder than the aluminum particles generally promoted deposition, although deposition onto aluminum alloy was difficult due to the presence of a tenacious oxide layer. Initiation was seen to be rapid on hard metallic substrates, even when deformation of the substrate was not visible. The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Sciences and Applying the Technology, International Thermal Spray Conference (Orlando, FL), May 5–8, 2003, Basil R. Marple and Christian Moreau, Ed., ASM International, 2003.     

基于博弈论的制造网络联盟合作伙伴的监督及激励机制设置

制造网络联盟企业是一种动态联盟,传统的企业的行政管理方法不适用,需采用新的方法和理论来指导其运行和管理.本文在建立了制造网络联盟企业的监督博弈模型的基础上,用纯策略和混合策略博弈均衡的原理讨论了监督机制的设置原则.此外,利用信息经济学的委托-代理理论,通过引入盟主的监督惩罚函数建立了双方博弈委托-代理模型.求解该模型,得到最佳分配系数以激励合作伙伴的投入;并对该系数进行讨论得到三条监督激励机制,为盟主设置合理的监督激励机制提供了理论基础.     

炼厂硫腐蚀的典型案例分析及解决措施

通过硫在不同温度与环境下对金属材料腐蚀的典型案例分析，简述其腐蚀机理与解决,工对今后炼厂高硫油加工提出进一步建议。     

Progress in flotation de-silica

1　INTRODUCTIONBayer sprocessisatypicalmethodtoproducea luminumoxidefrombauxite .Forthediasporic baux ite ,theBayer sprocesscaneconomicallyproducealu minumoxideonlywhenthemassratioofAl2 O3toSiO2 >10 .However ,inChina ,thealuminumoxidewasmainlyproducedbyusing“sinteringprocess”or“in parallelBayer sinteringcombination process”technologiesbecausethediasporic bauxiteischarac terizedbyhighcontentofaluminumoxideandsilicabutlowAl2 O3/SiO2 (average 5 6 ) .Thesetwotech nologieshavetheproble…